The Bank of England has warned that criminal prosecutions could follow the defacing of banknotes with anti-Israel slogans.
Currency with the words “Free Palestine! Boycott Israel!!!” stamped on them have appeared in Bolton, the Daily Mail reported.
Separate images have also appeared on Twitter of bank notes defaced with the same slogan in handwriting, with some Twitter users encouraging the public to follow suit.
While defacing British currency is illegal, the bank notes remain legal tender.
A spokesman for the Bank of England said: “Defacing bank notes is definitely not something we would recommend but whether or not there would be a prosecution would be up to the Crown Prosecution Service to determine if it was in the public interest.
“The notes are legal tender but they would probably be taken out of circulation when they entered our processing plants.”